Status Updates From The Harvard Medical School ...

"Two final caffeine points: Be aware that in addition to beverages, chocolate and certain cold medications (check the label) can contain significant amounts of caffeine." -- !!!

"The underlying mechanism for exercise’s sleep-enhancing effect has not been conclusively determined. One theory is that regular exercise and the subsequent increase in physical fitness that results boosts the brain’s production of serotonin, a chemical that promotes sleep."

"“Bad” naps come up most often in the context of people with chronic insomnia. These people often get less than six hours of sleep at night, leading them to feel sleepy during the day. Giving in and taking a nap—especially a long one—only perpetuates the cycle of nighttime insomnia and daytime sleepiness."

"Doctors used to reassure older people that they needed less sleep than younger people to function well, but sleep experts now know that isn’t true. At any age, most adults need seven and a half to eight hours of sleep a day to function at their best. (..) Not surprisingly, the older we get, the more likely we are to supplement nighttime sleep with daytime naps."

"We know, for example, that the brain’s natural production of the hormone melatonin decreases significantly during adulthood and old age."

"A different 2004 study found that men limited to four hours of sleep for two consecutive nights experienced hormonal changes—specifically, decreases in the hormone leptin and increases in the peptide ghrelin—that made them feel hungry and crave carbohydrate-rich foods such as cakes, candy, ice cream, and pasta. Researchers feel that constant sleep debt is associated with obesity."

"Two potentially dangerous phenomena can occur among sleep-deprived people: microsleeps and automatic behavior. (..) Automatic behavior refers to a period of several minutes or more during which a person is awake and performing routine duties but not attending to their surroundings or responding to changes in the environment." -- 헉 요며칠의 나.

"Then there are the times when circadian and homeostatic factors are at odds. (..) In this situation, it’s hard to predict which drive will win—it’s a battle that can go either way." -- 앞으로는 웬만하면 수면시간 가지고 장난치지 말아야겠다.

"The homeostatic drive also influences the timing of sleep. It has two aspects: elapsed time since last sleep and cumulative sleep debt."

"In a young adult, normal sleep architecuture usually consists of four or five alternating non-REM and REM periods. Most deep sleep occurs in the first half of the night; as the night progresses, periods of REM sleep get longer and alternate with Stage 2 sleep. Later in life, the sleep skyline will change, with less deep sleep, more Stage 1 sleep, and more awakenings." -- 나이가 든건가! ㅜㅜ

'Although largely self-regulating, the clock responds to several types of external clues to keep it set at twenty-four hours. Scientists call these cues zeitgebers, a German word meaning “time givers.” Key zeitgebers include light, time cues, and melatonin.'

'Dreaming occurs during REM sleep, which has been described as an “active brain in a paralyzed body.”'

'Sleep specialists have called non-REM sleep “an idling brain in a movable body.”'

"Sleep debt is cumulative. Studies have shown that performance on tests of alertness and thinking continues to get worse the longer sleep deprivation lasts. In other words, we do not adapt to sleep deprivation."